1. Field of the Invention
The present invention relates to a drive, primarily for optical light forming means, which light forming means can be used in a projector, which projector comprises light generating means, which light generating means form a light path passing through light forming means, which drive comprises at least one motor, which motor can be mechanical connected to at least one optical light forming means, which light forming means comprises at least partly open area for light, where at least two light forming mean are cooperating in a light path for forming the light, which light forming means are rotated around a common axis in and out of the light path.
2. Description of Related Art
U.S. Pat. No. 6,687,063 concerns units for projection of profiled images and for floodlighting suffer from a trade off between the quality of the illuminated field and efficiency. The hue, saturation, and intensity must be continuously controllable, and the quality of the illuminated field must be even. According to the invention the optical components have been refined according to a general principle which enables the use of efficient elliptical reflectors without a reduction in quality for both purposes. Each color is controlled by relatively moveable filters having a comb like structure in which the design of the individual teeth compensates for the interaction of the many variables. The intensity is controlled by mechanical dimmers which are designed according to the same principles. This construction will also improve the quality of condenser type projection systems.
U.S. Pat. No. 6,402,344 concerns a linear effect device for independently and simultaneously rotating two effect discs with in a single axis for use in a conventional illumination system. The rotation of the second effects disc modifies the continuous images generated by the rotation of the first effect disc.
U.S. Pat. No. 6,402,344 operates by means of two independent motors. These motors are mechanically coupled to each color forming object which objects can be moved completely independent of each other. The system is used for letting the color forming means rotate about the axis in a continuous rotation. By this invention, it is possible to let the two light forming objects rotate in the same or in different directions simply by controlling the motors. Synchronizing the two motors for operating opposite to each other will be very difficult for all known motor types. Typical small DC or AC motors will not operate with exactly the same speed. Typically in projectors, step motors controlled by computer means are used. There is one problem regarding the step motors in that they might lose one ore more steps in relation to the controlling computers. This happens often during normal operation and a reset of a zero position for the motor is to be performed in order to ensure the correct position. If step motors must operate synchronously, this can only be achieved by placing special measuring and feed back circuits at the rotating axis for a continuous measuring of the actual position and compensate for failures by adjusting the motor position.
U.S. Pat. No. 941,752 describes an attachment for a projection apparatus, which attachment concerns external shutters placed in front of a projector. The shutter blades are rotating around a common axis. The shutters are provided with arms, by means of which they are moved upon their pivots, and said arms are connected to an operating rod by means of links, which links form a pair for each shutter.